[dontfeedphils]

What would the point of such a comment be? The same output is the same output. It can not possibly have a different impedance.

Differences in the trace geometry leading to the connectors on the PCB may lead to slightly different impedance values.

 

[Hooster]

Differences in the trace geometry leading to the connectors on the PCB may lead to slightly different impedance values.

Seriously? How much difference?

 

[dontfeedphils]

Seriously? How much difference?

I don't have the information (PCB layout) or knowhow to answer that question, unfortunately.

 

[LCMusicLover]

Hi Everyone

Does your Hugo 2 get hot while playing hiRes? Mine does and I'm rather worrried

Thanks

Mine gets pretty hot when playing while charging. Not so much when playing but not plugged in.

 

[Daniel Johnston]

What would the point of such a comment be? The same output is the same output. It can not possibly have a different impedance.

It is a terse response for sure. The context for the response was from people hearing a difference from the Hugo 2 directly vs through a headphone amp. Whether the RCA output is 100% identical in every way to the headphone out (including impedance) is known only to the designer. I'm sure Rob Watts didn't optimize the RCA outputs to drive headphones or IEMs directly. Nor do I think there is any design flaw or issue with the RCA outs.

You now have two recent examples on this thread of people hearing a sonic difference driving headphones from the jack vs RCA directly. Yes, it could be cabling, synergy, or another factor causing the difference. Feel free to replicate my scenario and come to your own conclusions.

In any case, I don't perceive this as anything more than a passing curiosity.

 

[Hooster]

Differences in the trace geometry leading to the connectors on the PCB may lead to slightly different impedance values.

How does trace geometry affect impedance? I never heard of this effect before but I would love to learn more.

 

[dontfeedphils]

How does trace geometry affect impedance? I never heard of this effect before but I would love to learn more.

https://www.sisoft.com/blog/posts/understanding-trace-impedance.html

 

[Hooster]

https://www.sisoft.com/blog/posts/understanding-trace-impedance.html

Impressive, many thanks. Perhaps Rob can help and tell us more about the difference between the RCA and headphone output impedance and all.

 

[michaelc]

I appreciate the input. However, the cable is of high quality (WyWires Red). I use it on the Mojo in the reverse fashion and have no issues. My unit is not an issue either as I connect it to my main system via RCA and it sounds amazing. My main system likewise is very resolving.

Rob Watts just said it was connected to the same output as the headphone jacks. He made no comment about impedance. Logically it should be the same or similar, I understand. Maybe my use of "much" was too strong. I should say it was noticeably different. The KSE1200s in general are amazingly resolving and detailed.

This was an observation supporting how running headphones/IEMs directly off RCA sounded different. I'd be curious if there are any other KSE1200 owners comparing the Hugo 2 RCA out vs 3.5mm out sonic differences. I doubt there are many of us out there. I also highly doubt there are many people that are running their IEMs/Headphones directly off of the RCA output in general. As with all audio discussion, I submit this with the disclaimer YMMV.

KSE 1200 need an amp between H2 and the iem itself?
Can you hear differences with other source as well?

 

[Focux]

hey all, sorry to hijack. are there any DS based chips that sound as transparent and as detailed as the H2? say 4499 or 9038Pro?

 

[Hooster]

KSE 1200 need an amp between H2 and the iem itself?

Yes.
" The premium KSE1200 Electrostatic Earphone System is an electrostatic earphone and amplifier system for use in‐line with portable media players. These single‐driver electrostatic Sound Isolating™ earphones provide an astounding level of clarity and detail for the most discerning audio aficionados. "
https://www.shure.com/en-US/products/earphones/kse1200

 

[michaelc]

hey all, sorry to hijack. are there any DS based chips that sound as transparent and as detailed as the H2? say 4499 or 9038Pro?

It depends on the implementation.
Example, you can hear differences sound signature of 4499 implementation between AK sp2000 and Hiby R8.

hey all, sorry to hijack. are there any DS based chips that sound as transparent and as detailed as the H2? say 4499 or 9038Pro?

Yes.
" The premium KSE1200 Electrostatic Earphone System is an electrostatic earphone and amplifier system for use in‐line with portable media players. These single‐driver electrostatic Sound Isolating™ earphones provide an astounding level of clarity and detail for the most discerning audio aficionados. "
https://www.shure.com/en-US/products/earphones/kse1200

Then I guess the amp might not transparent enough to hear the differences.
This might be a good thing coz it will retain the Shure house sound regardless sources.

 

[Daniel Johnston]

KSE 1200 need an amp between H2 and the iem itself?
Can you hear differences with other source as well?

Since they are electrostatic, they require an energizer.
I find them source dependent, yes. You need a pretty good DAC to get their full potential. They aren’t forgiving.

 

[Rob Watts]

I don't have the information (PCB layout) or knowhow to answer that question, unfortunately.

So the way this happens is when I design the PCB layout we have a reference point - this is where the feedback path for the DAC amplifier is taken - and so I set this reference point to be as close as possible to the headphone outputs, as it's the headphone outputs that need the lowest impedance. The RCA phono thus has an extra track length and for Hugo 2 that is an extra resistance of 3 milliohms. For driving loudspeakers, this would produce a tiny SQ change with the RCA phono sounding a tiny bit less precise, a bit softer and warmer in the bass. But I can't imagine this would be audible with headphones, as the impedances are much higher, and the back emf energy much lower too (particularly for planer headphones).

A much more likely explanation is the quality of the connectors being used. The connectors on Hugo 2 went through a process of evaluation and testing - even involving ripping the connectors apart - and I am confident in the SQ of the connectors used. But of course I have no control over the connectors and cabling you use, and that perhaps is more likely to explain any SQ differences.

 

[Daniel Johnston]

So the way this happens is when I design the PCB layout we have a reference point - this is where the feedback path for the DAC amplifier is taken - and so I set this reference point to be as close as possible to the headphone outputs, as it's the headphone outputs that need the lowest impedance. The RCA phono thus has an extra track length and for Hugo 2 that is an extra resistance of 3 milliohms. For driving loudspeakers, this would produce a tiny SQ change with the RCA phono sounding a tiny bit less precise, a bit softer and warmer in the bass. But I can't imagine this would be audible with headphones, as the impedances are much higher, and the back emf energy much lower too (particularly for planer headphones).

A much more likely explanation is the quality of the connectors being used. The connectors on Hugo 2 went through a process of evaluation and testing - even involving ripping the connectors apart - and I am confident in the SQ of the connectors used. But of course I have no control over the connectors and cabling you use, and that perhaps is more likely to explain any SQ differences.

Thanks Rob for the detailed response. It’s always interesting to hear your reasoning behind design choices.

Unless there is some academic merit for further experimentation, I will run the KSE1200 off the headphone jack and reserve the RCA for the main system.